1. Field of the Invention
This invention pertains to the field of surfboard construction. More particularly, the invention concerns a unique shallow draft surfboard fin socket for location in a recess formed in the bottom surface of a surfboard.
2. Description of the Prior Art
Much has been written about surfboards, the long, plank-like devices that young people use as a vehicle to ride on the top of incoming waves. While surfboards take on a variety of sizes and shapes, they generally can be defined as consisting of a length of foam as a core, defined by elongated curved sides, a generally pointed front end and a round or blunt rear end, where the broad top and bottom surfaces are spaced-apart, the top surface used to support the body of the rider, while the bottom surface contains fins that act as rudders to help in directing the board over the water. Current practice is to cover the foam core with at least one layer of curable resin-impregnated fiber material, such as glass fiber matting, and finish the board to a high gloss with one or more layers of a gel coat.
The fins extending from the bottom surface of the surfboard down into the water over which the board is passed are generally thin with sharp marginal edges and extend outward from the board from a straight fin base. Depending upon the size, shape and style of the surfboard, there may be a single large fin or a plurality of smaller fins in spaced-apart arrangement for use in controlling the direction of travel of the board. To insure that the fins remain in strong attachment to the board and in rigid position therewith, the fin base is usually anchored in a fin socket that is anchored in the foam core of the board.
Fin sockets are of two general types. The first type is a fin socket anchored in the foam core in which the fin is removably mounted. The removability of the fin is in recognition of the difficulty to package a surfboard having the fins extending therefrom and further is in recognition of the dangerous character of extended fins as the board is swung or moved from a transport vehicle, such as an automobile, and carried through a busy beach to the ocean where numerous young people may be in crowded attendance. Some of these removable-type designs allow the fin to be moved and reset in an elongated fin mount, at the discretion of the user, to change the riding characteristics of the board. A metal fastener is used to hold the fin in position in the box.
The second type of socket is of the permanent variety where a box-like socket is first adhesively anchored in the core of the surfboard and has an outwardly opening slot in which the fin is inserted along with sufficient adhesive to make the joint therebetween of a permanent nature. This type of fin mounting does not permit adjustment of the fin in the socket or for removal of the fin for transport, movement through a crowd, or otherwise.
With respect to the removable-type fin mounting, complaints from surfboard manufacturers that the socket is too deep and thus adversely affects the strength, surface gloss and finish of the surfboard has spurred development of a shallow fin socket for removably holding the fin therein. The depth of the fin socket is thought to be important from the standpoint of providing sufficient bonding area between the fin anchor box and the foam. Efforts to make a shallower box have led to a loss of this anchoring surface with the result that the box becomes loose during use of the surfboard in rough water and allows the influx of sea water which further deteriorates the bonding therebetween and ultimately results in the loss of the fin.
One approach to making a shallower draft fin box is shown in U.S. Pat. No. 4,804,347 where the sides of the box are slanted outward to provide greater surface area of contact with the underlying foam core. This particular design has unwittingly created a pair of spaced-apart sealed air pockets in the housing that, upon exposure of the surfboard to sunlight, such as when the surfboard is carried upside down on the top of a vehicle, has caused air in these pockets to undergo expansion with the result that the foam is ruptured about the air pockets leading to destruction of the joint between the fin socket and the surfboard. In addition, in this particular design, glass overlying external ribs formed in the top surface of the housing does not bend appropriately enough about the attachment ribs thereby allowing the formation of air bubbles thereunder which often expand during this heating process and make open holes in the bottom of the board thus allowing the influx of sea water and the accompanying damage created thereby. In all situations, where the fin is permanently attached to the bottom of the board, should the fin encounter an obstruction during use of the surfboard, the fin may undergo damage up to and including breakage that is not repairable and thus the surfboard owner suffers total loss as the result of damage to one or more fins.
Finally, where fins are removably attached to such anchor boxes, often the stress applied to the fin during use or upon the fin striking a solid object, is transmitted completely to the rear of the fin base thus applying significant stress to a small portion of the fin anchor box and raising the potential for the box to suffer damage such as cracking of the rear walls of the fin box and allowing the entrance of sea water, etc. In addition, all metal fixtures and fasteners suffer corrosion in sea water and require constant attention and/or replacement.
Accordingly, there exists a need for a shallow draft surfboard fin socket for use in surfboards to allow quick and easy removal and reinsertion of fins in the surfboard to accommodate a variety of situations during transportation, use and maintenance of the boards.